This invention relates generally to the production of commodity and specialty chemicals and, more specifically to an integrated bioprocess for producing methyl ethyl ketone (MEK) and 2-butanol.
MEK is a four carbon ketone that is mainly used as a large volume solvent for coatings, adhesives, and inks, as well as a chemical intermediate. The main commercial route to MEK is the dehydrogenation of secondary butanol (s-butanol). The requisite s-butanol is accessible via sulphuric acid hydration of n-butene. In converting s-butanol to MEK, the alcohol vapour is fed into a multi-tubular reactor containing zinc or copper oxides as catalysts. The reaction is conducted between about 400-500° C. and at pressures of less than 4 bar. Liquid phase technology is also employed using Raney nickel or copper chromate at 150° C. Hydrogen is flashed off and the condensate is dehydrated by fractionation. The MEK phase separates from a water-ketone azeotrope obtained and is further purified by distillation.
Another method for MEK production involves the direct oxidation of n-butene in solution using palladium and cupric chlorides as catalysts. MEK can also be made as a by-product in butane-based acetic acid manufacture. Still another process has been developed in which MEK is available as a byproduct from phenol production. In this phenol manufacture, MEK and acetone are produced as byproducts.
Many of these processes are energy intensive requiring elevated temperatures. Catalyzed processes for the production of MEK can require expensive metals as well. Thus, there exists a need for compositions and methods that reduce the use of petroleum-based synthesis of MEK, as well as 2-butanol. The present invention satisfies this need and provides related advantages as well.